﻿<!DOCTYPE html>
<html>
<head>
  <title>Using Dimensioning Links</title>
  <!-- Copyright 1998-2020 by Northwoods Software Corporation. -->
  <meta name="description" content="Dimensioning Links show the distance from a spot on a node to another spot on a node." />
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <script src="../release/go.js"></script>
  <script src="../assets/js/goSamples.js"></script>  <!-- this is only for the GoJS Samples framework -->
  <script src="../extensions/DimensioningLink.js"></script>
  <script id="code">
    function init() {
      if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this
      var $ = go.GraphObject.make;

      myDiagram =
        $(go.Diagram, "myDiagramDiv",
          {
            "undoManager.isEnabled": true
          });

      // A simple resizable node
      myDiagram.nodeTemplate =
        $(go.Node, "Auto",
          { locationSpot: go.Spot.Center },
          new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
          { resizable: true },
          $(go.Shape, { strokeWidth: 0, fill: "lightgray" },
            new go.Binding("fill", "color")),
          $(go.TextBlock, { margin: 10 },
            new go.Binding("text", "key"))
        );

      // A generalized example template using a DimensioningLink.
      // Most usage might not have so many Bindings.
      myDiagram.linkTemplateMap.add("Dimensioning",
        $(DimensioningLink,
          new go.Binding("fromSpot", "fromSpot", go.Spot.parse),
          new go.Binding("toSpot", "toSpot", go.Spot.parse),
          new go.Binding("direction"),
          new go.Binding("extension"),
          new go.Binding("inset"),
          $(go.Shape, { stroke: "gray" },
            new go.Binding("stroke", "color")),
          $(go.Shape, { fromArrow: "BackwardOpenTriangle", segmentIndex: 2, stroke: "gray" },
            new go.Binding("stroke", "color")),
          $(go.Shape, { toArrow: "OpenTriangle", segmentIndex: -3, stroke: "gray" },
            new go.Binding("stroke", "color")),
          $(go.TextBlock,
            {
              segmentIndex: 2,
              segmentFraction: 0.5,
              segmentOrientation: go.Link.OrientUpright,
              alignmentFocus: go.Spot.Bottom,
              stroke: "gray",
              font: "8pt sans-serif"
            },
            new go.Binding("text", "", showDistance).ofObject(),
            new go.Binding("stroke", "color"))
        ));

      // Return a string representing the distance between the two points.
      // This is the cartesian distance if this.direction is NaN;
      // otherwise it is the orthogonal distance along that axis.
      function showDistance(link) {
        var numpts = link.pointsCount;
        if (numpts < 2) return "";
        var p0 = link.getPoint(0);
        var pn = link.getPoint(numpts - 1);
        var ang = link.direction;
        if (isNaN(ang)) return Math.floor(Math.sqrt(p0.distanceSquaredPoint(pn))) + "";
        var rad = ang * Math.PI / 180;
        return Math.floor(Math.abs(Math.cos(rad) * (p0.x - pn.x)) +
          Math.abs(Math.sin(rad) * (p0.y - pn.y))) + "";
      }

      myDiagram.model = new go.GraphLinksModel([
        { key: "Alpha", loc: "0 50" },
        { key: "Beta", loc: "150 0" },
        { key: "Gamma", loc: "100 150" }
      ], [
          {
            from: "Alpha", to: "Beta", category: "Dimensioning",
            fromSpot: "TopRight", toSpot: "TopLeft"
          },
          {
            from: "Alpha", to: "Beta", category: "Dimensioning",
            fromSpot: "TopLeft", toSpot: "TopRight", extension: 50, color: "blue"
          },
          {
            from: "Alpha", to: "Beta", category: "Dimensioning",
            fromSpot: "TopLeft", toSpot: "TopLeft", direction: 270, color: "green"
          },
          {
            from: "Alpha", to: "Beta", category: "Dimensioning",
            fromSpot: "BottomRight", toSpot: "BottomRight", direction: 90, color: "purple"
          },
          {
            from: "Alpha", to: "Beta", category: "Dimensioning",
            fromSpot: "Center", toSpot: "Center", extension: 50, direction: NaN, color: "red"
          },

          {
            from: "Gamma", to: "Gamma", category: "Dimensioning",
            fromSpot: "TopLeft", toSpot: "TopRight", direction: 0
          },
          {
            from: "Gamma", to: "Gamma", category: "Dimensioning",
            fromSpot: "TopRight", toSpot: "BottomRight", direction: 90
          },
          {
            from: "Gamma", to: "Gamma", category: "Dimensioning",
            fromSpot: "BottomRight", toSpot: "BottomLeft", direction: 180
          },
          {
            from: "Gamma", to: "Gamma", category: "Dimensioning",
            fromSpot: "BottomLeft", toSpot: "TopLeft", direction: 270
          }
        ]);
    }
  </script>
</head>
<body onload="init()">
  <div id="sample">
    <div id="myDiagramDiv" style="border: solid 1px black; width:100%; height:400px"></div>
    <p>
      This sample makes use of the DimensioningLink class, which inherits from the <a>Link</a> class.
      That class is defined at <a href="../extensions/DimensioningLink.js">DimensioningLink.js</a>.
    </p>
  </div>
</body>
</html>